#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main(void) {

	char grade;
	scanf("%c", &grade);

	switch (grade)
	{
		case 'A':
		printf(">=85");

		case 'B':
		case 'C' :
			printf(">=60");
		case 'D':
		printf("<60");
	default:
		printf("error.");

	}
}